The present invention relates to an additional telephone equipment and method for protecting against nuisance calls.
A conventional simple additional telephone equipment which can take the place of an automatic answering telephone device has already been proposed in the prior art, for example, JAPAN S48-75106 A (Serial No. S47-128078). This equipment generates a dummy busy tone, after a telephone line is engaged in response to an incoming call, to cause the calling party not to call again temporarily.
However, in the above example of the prior art, the calling party is caused to hear only the dummy busy signals at all times after engaging of telephone line. Thus, the general calling party is made to believe that this busy signal is tricky and artificial and does not try to call again.